Bump default 's2s_timeout' value (#3653)

Wait for an hour before closing an idle s2s connection.

It's not uncommon for a connection to be idle for longer than ten
minutes but less than an hour.  For example, XEP-0410 suggests a ping
interval of fifteen minutes.  A longer idle timeout avoids the latency
and log entries associated with constantly re-establishing such
connections.

Co-authored-by: Paweł Chmielowski <pawel@process-one.net>

src/ejabberd_options.erl

@@ -644,7 +644,7 @@ options() ->
      {s2s_protocol_options, undefined},
      {s2s_queue_type,
       fun(Host) -> ejabberd_config:get_option({queue_type, Host}) end},
-     {s2s_timeout, timer:minutes(10)},
+     {s2s_timeout, timer:hours(1)},
      {s2s_tls_compression, undefined},
      {s2s_use_starttls, false},
      {s2s_zlib, false},

src/ejabberd_options_doc.erl

@@ -1172,7 +1172,7 @@ doc() ->
       #{value => "timeout()",
         desc =>
             ?T("A time to wait before closing an idle s2s connection. "
-               "The default value is '10 minutes'.")}},
+               "The default value is '1' hour.")}},
      {s2s_use_starttls,
       #{value => "true | false | optional | required",
         desc =>